Dolphin 1

Two people can cling to the Dolphin 1 at once: the remote-controlled lifebuoy from OceanAlpha, a Zhuhai-based maker of unmanned surface vessels with a Hong Kong office, is rated to float 150 kg on top of its own 32 kg of buoyancy.

Unveiled in 2017, the orange device measures 119 × 85 × 20 cm and weighs 13 kg; two water-jet thrusters push it to 12 km/h for about 30 minutes, and the radio link reaches 800 m according to the datasheet (other sources say 500 m). Two strobe lights help crews spot it in the water; the datasheet lists no onboard sensors.

OceanAlpha demonstrated the Dolphin 1 in Brazil in February 2023 and claims use by beach rescue and coast guard units in China, though individual deployments are not documented. No price appears in the datasheet or press coverage, so pricing is on request. Sources disagree on speed (12 km/h, 4–5 m/s, nearly 10 mph) and capacity (150 kg versus 225 kg); the 2017 datasheet is treated as primary here.

The American EMILY is three times faster and has been on the market since 2010, but floats only 68 kg. For lifeguards weighing speed against the number of people a buoy can hold, the two designs mark the opposite ends of the class.